A world record from Christian Sprenger; No more mistakes from Aaron Peirsol (see 200m back below)

Men's 200m breaststroke semi-finals

Christian Sprenger (AUS) sprung a full-Jaked surprise in the first semi-final with a 2:07.31 blast that took down the world mark of Kosuke Kitajima (JPN) by 0.2sec. The quadruple Olympic champion, Kitajima caused a storm last year by insisting that his federation tear up contracts with suit makers so that he could wear the fast suit of the moment, the LZR. He did and retained his Olympic crowns.

With 15m to go in the second semi, Eric Shanteau and his X-Glide, already bronze medal winners in the 200m medley tonight, broke away from the seven men he had raced in a line with to claim lane 5 in the final on 2:07.42.

Sprenger's was the 27th world record of the meet. The all-time record of records is about to fall.

Back to breaststroke, The 2:09.80 in which the Olympic champion claimed the 2007 crown would have placed him 13th this morning at the sliding shampionships in Rome. Brenton Rickard (AUS) took silver in Melbourne in 2:10.99: euivalent to 18th in Rome heats. In semis, Kitajima's time would have placed him 15th. The world record that stood at 2:08.50 until last year to Brendan Hansen (USA) would have struggled to make the cut: last man in 2:08.63.

RIP 2:10.16: In January 2008, the monumental world-record time of Mike Barrowman (USA) remained solid and steadfast at No4 on the all-time ranking. The three men above him on the list had surpassed his time 14 times between them. Now, 81 times are faster, 43 of them clocked this year.

Some stats on the breaststroke race:

Rome 2009

Top 8 through: 2:07.31wr - 2:08.63

Inside 2:08: 3

Inside 2:09: 8

Inside 2:10: 14

Inside 2:11: 16

Melbourne 2007:

Top 8 through: 2:10.30 - 2:14.63 (one DQ)

Inside 2:08: 0

Inside 2:09: 0

Inside 2:10: 0

Inside 2:11: 1

Inside 2:12: 6

Inside 2:13: 9

Inside 2:15: 15

There are few, if any, events that demonstrate the impact of a bit of air trapping between body and suit.

Men's 200m backstroke semi-finals

Aaron Peirsol rarely, if ever, makes the same mistake twice. Three days after the Olympic champion failed to qualify for the 100-meter backstroke final at the world championships, the American has a new strategy for Thursday's semi-finals in the 200 back.

"It's my only individual swim now. I'll be gunning for it absolutely - probably more so than usual," Peirsol said after qualifying second in morning heats. "It will be much safer, much safer."

And so it was: Peirsol went through in 1:54.06, a championship record, inside the 1:54.32 in which Ryan Lochte (USA) claimed the crown in 2007. This time, and after his medley victory and world record, Lochte, went through in 5th place, on 1:55.39, a hand slower than the first world record held by Peirsol back in 2002. Peirsol now holds the world record at 1:53.08. The danger comes from one of the many in backstroke who are wearing leggings and one of those now considered widely to be among the most aesthetic and technically brilliant swimmers at these championships: Ryosuke Irie, on 1:54.14.